Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Some content-based video retrieval (“CBVR”) systems can extract content features from video in order to characterize the video. When a user submits a query containing desired features, the CBVR systems can retrieve relevant videos having extracted content features that match the user-submitted desired features. These extracted content features may include low-level static features that are extracted from one or more frames in the video. Some examples of low-level static features may include colors, textures, and shapes of objects within the video. In addition to the low-level static features, the extracted content features may also include motion features, which describe the movement of objects within the video. However, conventional approaches for extracting motion features may not be effective or efficient for video retrieval applications.